Phonograph record



Aug. 30, 1932. A. A. MCMANN 1,875,086

A PHONOGRAPI-I RECORD Filed Nov. 28, 1950 No. 1,421,045, of

I Patented Aug. 30, 1932 UNITED STATES PATENT OFFICE ARTHUR A. MCMANN, OF UTICA, NEW YORK, ASSIGNOR TO REMSEN CORPORATION, OF

- NEW YORK, N. Y., A CORPORATION OF DELAWARE PHONOGRAPH RECORD Application filed November 28, 1930. Serial No. 498,763.

This invention relates to phonographs and particularly to phonograph records made from sheet stock and has for an object, to prevent records, of this type, from warping; second to substantially separate the portion of the record surface receiving the sound grooves from the central portion of the record; another object of the invention is'to provide apertures in the sheet stock of the record whereby its adhesion on the turntable is increased. Other objects of the invention will appear from the following specification and illustrated in the .accompanying drawing, in which:

Fig. 1 is a plan view of a turntable with the record mounted thereon in accordance with the invention;

Fig. 2 is a side elevation of the construction shown in Fig. 1; and,

- Fig. 3 is an alternative form of the invention.

The introduction of phonograph records made from sheet stock such as the aluminum records disclosed in the 'Wadsworth Patent June 27, 1922, has made it desirable to increase the adhesion between the smooth surface of the record and felt surface of the phonograph turntable to prevent slipping; also it is desirable, when rec- 30 ords of this type are made from very thin stock, to prevent the record from warping or buckling, so that it will always lay flat on the turntable. It' is desirable to imprint, by lithography or by a printing process a dison the central portion of the record. This subjects'the central portion to certain stresses which tend to create warping. These conditions are overcome in the present inven-' g tion by separating, as far aspossible, the

4,0 central portion, of the record from the outer portion, which receives the sound grooves. This is secured by stenciling an aperture in the record between the outer portion and the central portion. This aperture may take the form of a pair of arcuate slots, located between the outer and inner portions of the record, or it may take the form of one or more rows of perforations, in the same location. When a record, so perforated, is placed 99 on the felt surface of a turntable the felt portion with the soundgrooves from the rest of the record.

In the drawing, 11 is the turntable mounted on the stem 17 of the phonograph mechanism 18. The turntable is provided with a felt surface at 12 upon which the sheet phonograph record 13 is placed with the stem 17 projecting through its central aperture.

The phonograph record has an outer portion 14 upon which the sound grooves are inscribed and an inner portion 16 surround ing the stem which may be lithographed or otherwise provided with a printed surface. Between the outer portion 14 and the inner portion 16, the arcuate slots 15 are provided, which are stenciled from the stock of the record, so that the inner and outer portions are connected at two points where these arcuate slots terminate. The felt surface 12 of the turntable partially projects into the slots 15 when the record is in place.

. In the modified construction in Fig. 3, the central aperture of 17a, the inner portion at 16 and this portion is separated from the outer portion by the double row of punched apertures 21 and 22 which, it will be noted, are placed in sta ered relation. These apertures are provided for the same purpose as the arcuate slots 15, in Fig. 1. It is apparent that the stock may be stenciled in a variety of forms in carrying out this invention whereby apertures are provided in-the stock of the record to be engaged by the felt of the turntable.

The record, or the record blank, 13 when subject to pressure on the inner portion, as in printing, does not transmit its internal stresses to the outer portion of the record, owing to the stenciled apertures which separate these two portions. For'the same the record is indicated at 2 ev-moss reason an stresses that may'arise from-impressing t e sound grooves onthe record are p not transmitted to the centralportion. It willbe noted that records-0f thls type, par- 5 tic-ularly when made of sheetia'lummum ere.

, light and. smooth landttheir adhesion on'Ithe' turntable is comparatively small, butby'providing'apertures throughthe stock of the rec- 0rd. a: gripping effect is obtained between the 10 record andithevturnta ble surface which'::as-

sists in preventing theslipping of ,the record blanks. v I

Haying thus described my invention, I I claim! 1 u 1. A sheet metal disc phonograph'record having anroutervpart-toreceive sound grooves and aninner part with an aperture toreceive the stemof a turntable, said innerxportion being of'the-same stock'as the sound-zgrooved 1g) 'partand said record disc having slottedapen;

,' tures betweensaid outer andinner parts.

. 2. A phonograph record disc of sheetmetaj having an outer part to receive sound grooves and'aninner part with an a 'erture to receive gs flgthe stemof a turntable an perforations-be 4 .tweensaidouter'andinner parts located's'uhv If stantiaily"adjacent'fsaid outer part. v p

' T'- 3tA phonograph record'disc of sheet metal 7 having an outer part to receive soundgrooves .30 and an inner'part with zen-aperture to receive 1 the stem=ofwti1rntab1e and arcuate perfore-- 'tions between saidouter and inner arts.

4. A phonographsrecord disc made from an integral sheet of meta l having a; coneentrie part upon which soimdgrooves are placed I and a second 'concenfirio 'partfand. arcuate 1 apertures in said ,dise etween parts. i

In testimony w affi ignature.

hereeii 

